CVE-2023-52895
📋 TL;DR
A race condition vulnerability in the Linux kernel's io_uring subsystem could cause buffer leaks when handling multishot poll requests. This affects systems running vulnerable Linux kernel versions with io_uring enabled. The vulnerability could lead to resource exhaustion or information disclosure.
💻 Affected Systems
- Linux kernel
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
Sustained exploitation could lead to kernel memory exhaustion, system instability, or potential information disclosure through leaked buffer contents.
Likely Case
Resource exhaustion causing performance degradation or service disruption in systems heavily using io_uring with multishot poll operations.
If Mitigated
Minimal impact with proper kernel hardening and monitoring for resource exhaustion.
🎯 Exploit Status
Exploitation requires local access and ability to trigger the specific race condition in io_uring poll operations. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel branches via provided git commits
Vendor Advisory: https://git.kernel.org/stable/c/36fc7317cdb16cfeae0f879916995037bb615ac4
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version
2. Reboot system to load new kernel
3. Verify kernel version after reboot
🔧 Temporary Workarounds
Disable io_uring
linuxRemove io_uring support from kernel (not recommended for production systems that rely on it)
echo "blacklist io_uring" >> /etc/modprobe.d/blacklist.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Monitor system for memory exhaustion and unusual io_uring activity
- Restrict access to systems to trusted users only
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare against patched versions. Vulnerable if using unpatched kernel with io_uring enabled.Check Version:
uname -rVerify Fix Applied:
Verify kernel version matches patched version and system is stable under io_uring load📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- Memory allocation failures
- System performance degradation
Network Indicators:
- None - local vulnerability only
SIEM Query:
Search for kernel panic logs or memory exhaustion alerts